See also:

How to Check Lubricant
To get an accurate reading, the vehicle should be on a level surface. If the level is below the bottom of the fill plug hole, located on the transfer case, the vehicle will need some lubricant ad ...

Customer Assistance Offices (U.S. and Canada)
GMC encourages customers to call the toll-free number for assistance. However, if a customer wishes to write or e-mail GMC, the letter should be addressed to: United States GMC Customer Assistance ...

Crew Cab
A. Open or Close B. Vent On vehicles with a sunroof, the sunroof only operates when the ignition is in the ACC/ACCESSORY or ON/RUN or the Retained Accessory Power (RAP) is active. See Retained Ac ...